I don't have a model X, but my Nav question is pretty generic.
I have a Mk3 version 3-1/21 in a 2001 740iL E38 that won't shut off with the car, and drains the battery in 3 days because of the Nav's 1/2 amp draw.

I simply need to know what controls a working Mk3 turning off? (Or, likely any other type of NAV in any BMW model). Is it controlled by a relay? Or, is the device itself supposed to turn off, from an internal timeout? I'd hate to just unplug the Nav for no other reason than this power drain while the car is parked and off.

The Nav works and displays properly, I can remove and re-insert the CD with no problems. The Mk3's OS version is 3-1/21, (which I might want to upgrade, if I can find a CDkey to upgrade, since only this model and version level needs that CDkey).